Carburetor



Y Feb; 17,` 1925.

. 1,526,318 M. G. CHANFJLER CARBURETOR Filed Aug. 2, 1920 2 Sheets-Sheet1 .Ill

Feb. 17, 1925.

M. G. CHANDLER CARBURETOR Filed Aug. 2, 1920 2 Sheets-Sheet 2 InventorUd/@0rd /Mmd/f ttor l 3.73

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Seam" Patented Feb.` 17, 192s. f l

lUNITED `STATES MILFonn e.

`1,526,318 PATENT- OFFICE.

cHANnLEn, or CHICAGO, ILLINOIS; AssIeNon, BY MnsNn ASSIGNMENTS,

To cUnrIs '13. cAMP, TRUSTEE, onoAK PARK, ILLINOIS.

' CARBURETOR.

Application-filed August' 2, 1920i Serial N0. 400,693.

To all lwhom t may-concern:

Be itknown that I, MILroRD G. CHAND- LER, acitizen lof the UnitedStates, and resi- `new and useful Improvement 'in ACarburetors, of whichthe. following is a full, clear, concisa-and enact description,reference beinghadto 'the accompanying drawings, forming a part of thisspecification.

, My linventlon relates to carburetors lfor `'internal combustionengines. The carburetor to which my inventionL is applied is arrangedfor lifting fuel froma low-level supply tank to the iioat chamber of thecar-f buretor by suction derived from the suction of the engine suppliedby the carburetor. It is well known that the power output of an internalcombustion engine is substantially proportional-to Athe actual pressureof the explosive mixturevin the intake manifold of the engine. Thenearer the pressure of this mixture approaches atmospheric pressure, thegreater-the power outprut of.

the engine, and the further this pressure falls below atmosphericpressure, the .less` the power output of the engine. The carburetorthrottle interposes a restriction to the passage of air into the enginemani-fold, capable of creating a high depression in the manifold, andthus depriving the engine of power.` With the `throttle wide openeyeryrestriction in -theintake passage creates a certain depressionthelpressurey of the i mixture in the intake manifold, and thus deprivesthe engine of ay portion ofthe power which it would develop were it notfor the restricted'intake. My invention vrelates to a carburetor inwhich means is lprovlded for securing a depresf-xion sufiicientforlifting fuel from a low-level sup'plytank to the carburetor withoutunduly restricting the passage leadinginto the carburetor.

. My invention relates further to a means for delivering fuel to theinrushing columnf of air at a point near the middle of' thev column 'sothat the distribution of fuel and air willbe substantially uniform.vThis is accomplished, as willbe more fully herein- '5 after pointedout, by arranging the Adis..

charge end of the fuel delivery tube sothat -1t `moves across the airintake opening, at

l 'substantially' one-.half therate that the' v'openingin sinarea' Mylnventlon is in the accompanying drawingsin which like reference g vtheseveral views, in whichdent of Chicago, in' the'county of Cook, and 5State of Illinois, have invented a certain taken onthe line-4 4 ofFigure 1 showingy the mechanism for introducing the yfuelinto themovable delivery nozzle.

l .Figure 5 is a .section taken on a broken lane to show the fuelpassageway from the ottom of the oat chamber to the,induc tion passage.yReferring rst to Figure 1, the carburetor `body comprises twomaincastings. 6 and 7, `the casting 6 including the principal portion ofthe induction passage andalso the float or fuel chamber, speciallyindicated at 8. The casting? is a fillet lying between the -two Wingsl() and 11 which constitute partsy of the main casting 6. These twowings are vinternally milled with parallel inner walls, the spacer l7serving to hold the free ends of the wings `in laccurately spacedrelation. Between the wings 10 and l1 is a shoe 14 pivoted at 15,' theshoe having oppo- Isite parallel `faces which clear the inner' sidewalls of the wings'lO `and ll1v by about 2/1000 yof an inch, 4so thatthe space back of the shoe is substantially.` enclosed and so that theshoe may act as-a piston swinging about its pivot 15to open and closethe' induction passage.- The shoe is preferably made hollow; andfbetweena boss 17` within the hollow` of the shoe andthe spacer v7 is a spring18 which tends to hold the shoe in the -position to `close the inductionpassage. The shoe is provided with openings-20 leading between theinduction passage and the lspace back of the shoe,.through which thesuction of the -induction passage ma be communicated-with Jthe spaeebacko thev shoe for opening the shoe. The `opposite wall 214 of theinduction passage is referably formed substantially-semi-cylin rlcallyat the point 22 and gradually blends from this semi-circulan cross 1section into a` straight cro section at the point 23, so that theinduction passage has generally flaring Ashape' of substantially th,sameproportions: a Venturi tube, the shape bemg such that no matterwhat the position of the shoe may be, the point of least cross-sectionalarea of the intake passage lies apside wall of the housing 6. By meansof a link 29 pivotally attached to the nozzle 27 at 30 and to the shoey14 at 31, the nozzle is caused to partake of the movement of the shoe tosuch an extent as to' maintain the delector 33 which is carried by themovable end of the nozzle 27 substantially midway between the shoe 14andits opposing wall 23 for all positions of the shoe, the purpose ofthis being to inject the mixture of fuel and air which passes out of the`hollow side of l, the deflector 33 into the middle of the stream of theiioat chamber.

of incomin air. v

Fuel is elivered to the ports 35 in the nozzle Venturi tube 28 through apassage 36 which leads to the lower part of the float chamber 8, thispassage being provided with a plug 37 having a properly sized openingthrough it to furnish the right amount-of fuel for a combustiblemixture. The upper space of the float chamber v8 is maintained at adepression below atmosphere for the purpose of lifting fuel to the floatchamber from a low level supply tank. The depression for this purpose isderived from the throat of a very small Venturi tube 39, shown insection in Figure 3, through a communicating passage 40 which connectsbetween the annular space 40 around the vacuum Venturi tube, and theupper space The Venturi tube 39 is drilled eccentrically, so that whenrotated within the housing 4l, the discharge e-nd of the Venturi tubewill be caused to change its position ywith respect to the pivot 15 uponwhich the shoe 14 is supported. The shoe is provided with a cam 43 whichis cut so that its edge 44 intersects the discharge opening of theVenturi tube 39. The rotation of the Venturi tube 39 causes the edge ofthe cam to cut off greater or less proportions ofthe opening to permitgreater or less amounts of air to pass through the Venturi tube. By therotation of this tube, the mixture may be made rich or lean, since theamount of air passing through this small Venturi tube controls theamount of suction on top of the fuel in the oat chamber. The ater thesuction on the top of the fuel m the float chamber, the less the fuel-Landais e feeding differential and, therefore, the leaner suit theparticular engine supplied by the carburetor. The spring 18. and otherparts of the carburetor are selectedto give a substantially constantproportionality of fuel and ain-,but if this proportionahty is notexactly what is desired to provide a perfect mixture under allconditions, then the richness at certain engine speeds can be governedby slight changes in the sha of the cam edge 44, as very few thousan thsof an inch taken from or added to this cam changes the mixtureproportions a noticeable amount.

The Venturi tube 39 is also provided with an opening 46 adapted toregister with an opening 47 when the Venturi tube is rotated to anextreme position. When these two openings 46 and 47 register, anatmospheric communication is completed to a point behind the shoe 14which relieves the suction back of the shoe and causes the shoe topartially close. vThis may be done in starting a cold engine, at whichtime an extremely rich mixture is needed.`

In the operation of this carburetor, the suction produced by therotation of the engine draws air through lthe nozzle Venturi tube 28which in turn draws a mixture of fuel into this nozzle through theopenings 35. This mixture of fuel and air is carried through the movablenozzle 27 and discharged into the induction passage just above thedeiiector 33.

causes a flow of air through. the small Venturi tube 39, thus creating asuction on the surface of the fuel in the float chamber for lifting fuelfrom the low level supply tank to the float chamber. Mechanism withinthe fioat chamber of ordinary construction maintains a substantiallyconstant level of fuel therein. When the throttle 25 is ol ned to a.greater extent than .that for i ling an engine, the increased suction inthe induc- At the same time,v the suction within the inductionpassagetion Ipassage of the carburetor is communicated through thepassage 2O to a point behind the Yshoe 14 and thus causes the shoe toopen to such an extent that the suction in the induction passage isprevented from increasing as rapidly as it otherwise would, this beingcontrolled by the pressure of the spring 18 which tends to hold the shoein its closed position. The openings 20 each being located at the pointof high local depression in the induction passage, the suction behindthe shoe 14 will increase much more rapidly than the rate of increase ofsuctiony in the largest art of the induction passage, thusvsubstantially overcoming the gradually increasing resistance of thesprin 18 as it becomes more and morecompresse Bv reason of this action,the suction in the induction passage of the carburetor at a point justanterior to the throttle 25. is prevented from very materiallyincreasing `as the ,volume of air through the induction passageincreases. It is necessary that the suction in the induction passageincrease t0 some extent to insure stability in the moving part-s of thecarburetor, but it is desirable Ifor securing the'best power resultsthat the depression in the induction passage be not` too greatlyincreased for the higher engine demands As the shoe 14 opens to itsvarious positions, the swinging nozzle 27'is caused to follow so thatthe fuel is delivered at the central part of the stream of incoming air,there being substantiall the. same space maintained` between'the eiector33 and the surface 23, as between the deflector 38 and the shoe 14 forall positions of the shoe.

This feature of my invention providingA means for ldelivering fuel tothe central part of the incoming stream of air is in no wise limited toa carburetor for lifting fuel from a low level sup-ply tank, and may beused with a carburetor in which the upper surface of the float chamberis open to atmosphere as well as in the present type of carburetor inwhich the upper space of the float chamber is sealed against externalat-- mos here.

A though my invention is shown and described with respect to the detailsillustrated on the accompanying drawings, it is to be understood that Ido not wish to be unduly limited thereto, certain modifications beingpossible without departing from the spiritor scope of my invention.

I claim:

. 1. In a carburetor, the combination with an inductionpassage having afixed wall, of

.abpivoted shoe constituting an opposite mov-l a e wall, a fuel deliverytube pivoted with- 1n the induction passage and-extending toward theanterior opening'into the induction passage, a deflector carried on theendof said tube, and means to Cause said tube and its deieetorv to moveabout its pivot to hold lsaid deflector and the movable end of the tubesubstantially midway between the xed wall ,of the induction chamber andsaid pivoted shoe for all of the various positions of said pivoted shoe.

, closed by a part of said Venturi tube, said Venturi tube being rovidedwith means for opening said secon passage when the Venturi tube isrotated to a predetermined position, and Imeans for delivering fuel to`said induction passage. 3. In a carburetor, the combination with aninduction passage, means for varying the size of the opening throughsaid passage, a fuel and air delivery port located 'at substantially'the' most constricted point in said passage, a Venturi tube forcreating a mixture of fuel and air, and a tubular connection extendinfrom said Venturi .tube in a downward direction to said fuel and airdeliveryl port, substantially vas described.

4. Ina carburetor, the combination with an induction chamber of aprimary mixture passageway lying longitudinally within the inductionchamber, a Venturi tube serving as a fuel nozzle discharging into saidprimary mixture passageway, a discharge orice `for said passageway wherethe .primary mixture discharges into the induction chamber, the point atwhich the primary mixture enters the primary mixture passageway beingnearer the engineto-be served bythe carburetor than the point at whichthe primary mixture discharges from the discharge

